matoos32/jfreechart-builder

Candlesticks and XY lines have pixel offset from one another

Closed this issue · 1 comments

matoos32 commented

From FIXME in OhlcPlotBuilder.java:

FIXME: Candlestick renderer offsets center of candle from x-axis start pixel. When rendering general xy lines, those line points are drawn at the x-axis start pixel. This causes indicator lines to be misaligned by a few pixels from the OHLC bars and may provide false signals to those looking at charts.

Found in v1.5.6
https://github.com/matoos32/jfreechart-builder/blob/v1.5.6/src/main/java/com/jfcbuilder/builders/OhlcPlotBuilder.java#L279

Since initial implementation:
56640dc#diff-5f7449896404872cdff11efafb7c20a7d63447f210b85aa749e71a76afb70631R238

Needs confirmation if still is or really is an issue.

matoos32 commented

I wasn't able to reproduce this either in time-gapped or gapless charts.

Using the latest develop a bit past v1.5.7, I simply replaced the hard-coded use of StandardXYItemRenderer with XYLineAndShapeRenderer in the OhlcPlotBuilder build() method. In the demo app this rendered a default black square on XY line data-points. The black squares appeared aligned with the horizontal center of the OHLC candles (bars), for both time-gapped and gapless charts.